On the coming job i have to do a new wiring on massive shop.Deal its between me and show owned.There its about 200 m2 place with shelf's where shoes and handbag have to display.+ reception + office + 3 toilets + shower .I don't have any problem to to this job but im not clear on the RCD protected.Main supply its 3P+N.Most of my previous work its with single phase and domestic.As i know the shops its classified as commercial premises.What its the requirement for RCD protection on this premises.I never see before 3 phase CU with RCD.I see Merlin Gerin CU with 3phase RCD as main switch but never like split board.What i have to do on this situation..